1 Have you ever noticed that cartoon images of the sun usually include a happy face? There's something about the sun that just makes us feel good. Maybe it's the warmth it provides or the way it brightens the sky as it peeks through the clouds after a storm. But beyond that warm, fuzzy feeling, the sun provides much more. In fact, life on our planet would not exist without the sun's energy.2 The sun is a huge ball of hot, glowing gases that lies at the center of our solar system. It contains about 70 of the 92 natural elements that occur on the earth. The sun is made up of about 75% hydrogen, 24% helium, and just 1% of other elements.3 The sun is one of billions of stars in the universe, and it is the earth's closest star. With a diameter of about 865,000 miles, the sun is only medium in size when compared to other stars. While some stars have a diameter 10 times smaller than the sun, others have diameters up to 10,000 times larger.4 When you look at the sun and moon as they appear in the sky, they seem to be about the same size as each other, but the diameter of the sun is actually 400 times greater than that of the moon. They only appear similar because the sun is 400 times further away from the earth than the moon!